Inbreeding Effects on Finger and Palmar Dermatoglyphic Variations in Some Indian Populations An Overview.
SUDIP DATTA BANIK1*
Guyana Journal, August 2009
Inbreeding effects on the genetics of quantitative traits in human populations have been examined by several studies in respect of anthropometric, dermatoglyphic, skin color grades, blood pressure and menarcheal age. The permanence and matchlessness of dermatoglyphic patterns on each anatomical area of an individual is well established. The genetic basis of the patterns and their sizes has also been worked out by various authors through familial correlations and patterns of frequency distributions. Inbreeding effects on finger and palmar dermatoglyphic traits were recorded in different populations in different parts of the world. It has been possible to focus on the genetics of various dermatoglyphic characters including toe and sole print patterns, to develop suitable methodologies for the purpose, mechanisms of asymmetrical expression of traits, inbreeding effects throwing light on the genetics of the traits, examining influence of autosomal and X-linked genes on the traits, besides new associations of various diseases and disorders and all these opened new dimension for utilizing dermatoglyphics in population genetics
The principal objective of the present investigation was to observe the inbreeding effects on finger and palmar dermatoglyphic characters in different endogamous human populations of both the sexes in India. The degrees of differences of inbreeding effects on dermatoglyphic traits between different inbreeding levels within and between populations have been estimated and compared. The inbreds with the non-inbred control samples were also compared in these aspects. The earlier works have been incorporated along with new results to verify and to scrutinize the hypotheses on inbreeding effects on dermatoglyphs.
The work was based on three series of fresh data from the adult individuals of both the sexes of Ansari Muslims, Telagas and Sheik-Sunni Muslim males of three districts in the state of West Bengal in India. In addition, some data of the adults of the Reddy, Mala and Pokanati Reddy castes of Andhra Pradesh, Qureshi Muslims of Uttar Pradesh and Sunni Muslims of West Bengal in India were re-examined for comparative study. Rolled finger and palm prints of left and right sides separately were collected and included in this study among 1511 males (607 inbreds and 904 non-inbreds) and 891 females (436 inbreds and 455 non-inbreds) of all populations. Hence, the total sample size of the study of both the male and female sexes combined were 2402.
RESULTS AND DISCUSSION
The Results exhibit consistent trend of rise of frequencies of both the whorls and the plain arches at the cost of the loops and tented arches in different inbred samples. This trend is observed to be accelerated with the rise of inbreeding coefficient (F). The consistent trend of decline of frequency of ulnar loops with clear and steady rise of radial loops in inbreds of both the sexes are also observed. The results support the hypothesis of homozygosity of the extreme pattern intensities (whorls and arches) on fingers and heterozygosity of the patterns with the middle range of intensity (loops and tented arches). Higher rate of increase of whorl frequencies with inbreeding in the females than the males suggests possible influence of X-linked genes for whorls. Trends of consistent rise of mean triradial number on fingers (trNF), total finger ridge count (TFRC) and absolute finger ridge count (AFRC) are observed among the inbred series of all samples. Dermatoglyphic variables on palms show consistent trend of rise of mean triradial number on palm (trNP), mean maximal atd angle and mean adt angle in inbreds. On the contrary, steady declines of mean td ridge count and ab ridge count are recorded in inbreds than the non-inbreds. Inbred samples of both the sexes display the excess of CV2 in respect of generally of all characters. In frequency distributions, clear modes suggest that at least a few major genes (homozygous) clearly segregate on inbreeding with lowering of heterozygotes in antimodes. This is illustrated by the appearance of bimodality in the inbred distributions of triradial number on fingers and palms (trNF and trNP), TFRC and AFRC in all samples with a few minor exceptions.
1. Datta Banik S. (2008). Inbreeding Effects on Dermatoglyphs in Human Populations. Ph.D. Thesis. Vidyasagar University. Midnapore. West Bengal. India (Unpublished).
2. Datta Banik S. and Mukherjee DP. (2009). Sexual dimorphism, inbreeding effects and bilateral variation of finger dermatoglyphic ridge counts in Ansari Muslim population at Nandigram in West Bengal. The Internet Journal of Biological Anthropology. Volume 3. No. 1. (On Line journal)
1 Department of Anthropology, Vidyasagar University. Midnapore, West Bengal. India.
2 School of Human Genetics and population Health (SOHGAPH), Kolkata. India.
*Address of correspondence
DR. SUDIP DATTA BANIK
DEPARTMENT OF ANTHROPOLOGY
VIDYASAGAR UNIVERSITY. MIDNAPORE. 721 102.
WEST BENGAL. INDIA.
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